The embodiments described herein relate to systems and methods for analyzing fault detection in an optical transport network (OTN). More particularly, the embodiments described herein relate to devices and methods for optical data unit (ODU) fault propagation and link recovery using ODU-delay measurement.
An optical communication can be implemented using an optical communication network involving multiple network elements that are physically interconnected through optical fiber links. An end-to-end connection (i.e., connection between a source node and a destination node) among network elements for the transmission of optical data signals is referred to as a communication path (or simply ‘path’). The optical data signals can be transmitted over the communication path as structured frame units with a predetermined frame rate.
For example, in an OTN, a source node can be connected to a destination node via a communication path involving multiple network elements. To start communication in the OTN, the source node (or source path terminating equipment (PTE)) can generates a data structure referred as an ODU. Before transmission of the ODU, the source node encapsulates the ODU into a structured frame unit referred to as an optical terminal unit (OTU) frame. The source node then transmits the OTU frame over the OTN using the connection path to destination node.
Over the optical communication network, the transmission of OTU frame from source PTE to destination PTE can sometimes undergo signal degradation due to reasons such as a fault in the connection path. In some instances, the occurrence of signal degradation can even lead to loss of the OTU frame, which results in the loss of data over the network. Accordingly, upon determining fault in the connection path of the network, a known method implements re-transmission of OTU frame over the OTN.
Moreover, the fault in the connection path and re-transmission of the OTU frame can sometimes cause delay in the end-to-end communication. Accordingly, a re-transmitted OTU will likely experience signal degradation and/or loss of the related OTU frame as experienced by the previously transmitted OTU frame(s). Thus, such a retransmission technique can negatively impact the efficiency of the OTN.
Some known routers/interfaces support ODU-based bit interleaved parity (BIP) Fast Rerouting (FRR). Such known routers/interfaces determine the signal degrade condition based on the ODU BIP-8 threshold count over a period of time on the ODU layer and when the signal degrade condition occurs, an ODU-based FRR is activated to switch to another protection link. This ODU-based FRR implementation is expensive and as a result not all routers/interfaces support ODU-based BIP FRR.
Thus, a need exists for improved ODU fault propagation and link recovery using ODU-delay measurement.